Re: Is this likely a bad caps issue?
Thanks everyone for the help. This is likely to be an issue that I will continue to watch. But in the end I think that since it has been stable with a UPS for almost a year, I will leave it as it is.
At this time, I am concerned that it might not be electrolytic caps but could be a short across other caps, so the only way to really be sure it is not a cap is to replace all of them (not just the electrolytic ones). This seems to be more work than I want to put into it at the moment given that everything has been stable for about...
einhverfr
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Last Activity: 11-19-2005, 01:41 PM
Joined: 11-16-2005
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Re: A bulge necessarily equals a bad capacitor?
Just for the record in order to help people who may read this later.
A domed/bulging capacitor always indicates a capacitor that needs to be replaced. And this may occur for reasons other than manufacturing flaws.
Electrolytic capacitors have one issue as a group. They have a liquid in them (the electrolyte mixture) which can boil when the cap overheates. To prevent uncontroled explosions, these caps are "vented" on the top usually with stamped lines in the aluminum foil casing. This means that...Leave a comment:
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Re: Is this likely a bad caps issue?
Well, they are not bulging. a fairly careful evaluation today, I have decided that the caps don't seem in any danger of blowing and that the current state is probably worth allowing to continue (things are stable with the UPS).
As I said, this doesn't look like a typical failure but looks like something capacitor-related. In other words, combined with noisy power input, these caps are not working properly to stabilize the power but they don't appear to be leaking or bulging. In other words maybe they just don't have as much capacitance...Leave a comment:
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Re: Plasma screen with picture anomaly
Well, I am not sure I can tell you that it is capacitors. Indeed, I would tend to think not. And it is tough to say without seeing it.
However regarding the horizontal wrinkles.
Pleasma screens are a bit different than normals CRT screens in that (like LCD's) they are without a refresh cycle on the screen. On a CRT, your scanning electron beam goes across one line at a time (the inspiration for this method was the plowing of a field, I kid you not) and when it finishes, it starts over again. With a plasma screen,...Leave a comment:
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Re: Bad caps? Or something else?
One more thing.
My guess is that you had an overheating PSU due to the fan failing. This happens. I have seen it happen before for a customer.
With ATX power supplies, this will inevitably cause two secondary issues: The first is that the power output goes bad resulting in all the symptoms you are describing. The issues are that the caps and/or transformer core are overheating and hence the power is not being filtered and/or converted properly (I think-- I am no electronics wiz yet).
The second is that...Leave a comment:
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Re: Capacitors with white crud on top
This might indicate a leak of an electrolyte mixture on the top. I assume that different brands use different mixtures. So it would be worthwhile getting this replaced.Leave a comment:
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Re: Is this likely a bad caps issue?
Brands of caps seem to be (I think) something like KQS (not sure about this one) and RLP. But I left the model number in the office so I will have to get that tomorrow.
FWIW, I don't think it is a standard case of bad electrolyte recipes. I am thinking that it is more likely that it might be some other manufacturing issue that has rendered the capacitors less effective than normal.Leave a comment:
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Re: Bad caps? Or something else?
Regarding PSU's. It does sound like a cap issue in the PSU.
However, let me explain something about wattage of PSU's. The required wattage is going to depend on a number of things including the number of hard drives and/or CDROM's you may have running at once. If you have an underpowered PSU it will usually give you consistant problems while booting or when running many drives at once.
150 an absolute minimum for a small desktop system and one can often find these to be underpowered if any extensions are made. However,...Leave a comment:
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Re: Do I have to change the caps?
I don't know if there is enough information to determine at this point whether the caps are the problem or not.
If your computer is locking up after 10-15 minutes of use there are a number of other things to check out. The first one is heat. Make sure your fans are working and your heat sink is not overly warm to the touch. Make sure your case and especially the heat sink and air intake areas are relatively free from dust. But the hallmark of this sort of heat issue is that the more you fight with it the worse it gets, and then when...Leave a comment:
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Re: Is this likely a bad caps issue?
I have recommended an electrician check out the wiring. The UPS did resolve the issue at least temporarily but I am worried about simply delaying a more serious problem. I have also done the following tests in this area:
1) checked out the AC voltage with my multimeter with the unit plugged into the other socket on the same outlet set and watched while the problem occurred (nothing showed up).
2) Checked out the DC output of the 12V and 5V power outlets on the PSU while the problem occurred (nothing...Leave a comment:
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Is this likely a bad caps issue?
Hi all... This is my first post here.....
I run a computer consulting and repair firm in rural Washington State. I have seen a very weird issue and I am wondering whether people here attribute it to bad caps.
I have a customer who has a system (ASROCK motherboard) which worked fine for a short period of time (three months). Then winter came. The computer would randomly power off several times a day. All other computers in this area would work properly (though the print server could not handle being on the same outlet as a laser printer which may indicate the quality...
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